I have the same truck and engine, but I don't have a clue what the real axel is.
I tow a trailer with the same weight you are talking about, and most of the time never even know it is there. ( I have over 4000 towing miles on it now)
My truck came with "Tow haul"
Make sure you have weight distribution bars and a sway bar and you should have no problem at all
We live in the steep mountains of NC, and with my last truck which was a Ford F-150 with the Tritan V-8, it would labor up the steep grades and I would have to stay in the truck lanes.
The Ram takes them easily at 50 MPH and if I need to I can use the passing lane.
Just don't ask me about that stupid 3" thick manual that comes with it !
Jack L
Jack & Nanci